.app_scroll_bar{position:fixed;bottom:80px;display:block;width:20px;height:79px;background:url(http://static.aceona.com/app_images/sprite_icon/app_icon_sprite_v4.png) no-repeat -25px -123px;display:none}
.app_scroll_bar:hover{background-position:0 -123px}
*html .app_scroll_bar{position:absolute}